import pandas as pd
import numpy as np

df = pd.read_csv('911.csv')
temp_list = df['title'].str.split(":").tolist()
cate_list = list(i[0]for i in temp_list)
df['cate'] = pd.DataFrame(np.array(cate_list).reshape(df.shape[0], 1))
result_list = df.groupby('cate').count()['title']
print(result_list)